Neonatal Jaundice

Jaundice occurs in ~60% of term and ~80% of preterm babies in the first week of life. Visual assessment of severity is unreliable. Kernicterus is a rare but potentially devastating complication.

Diagnostic strategy

• Probability: physiological (days 2–5); ABO incompatibility (first 24 hours); breast milk jaundice (late first week).
• Serious, not to miss: ABO incompatibility; biliary atresia; haemolysis (ABO incompatibility or G6PD deficiency); sepsis.
• Other: drugs; hypothyroidism; hereditary spherocytosis; polycythaemia.

Assessment

• Is the infant unwell? Sepsis or GIT obstruction can both cause jaundice.
• Dehydration or poor weight gain can exacerbate jaundice.
• Jaundice before 48 hours of age suggests haemolysis.
• Jaundice starting after day 3 is more likely pathological.
• Birth trauma causing significant bruising? Maternal blood-group incompatibility? Family history of haemolytic disease?
• Dark urine or pale stools both suggest biliary obstruction.
• Cephalocaudal progression (head → trunk → palms/soles) is an unreliable sign but may hint at rough severity.
• Assess for plethora (polycythaemia) and hepatosplenomegaly (viral hepatitis/metabolic disease).

Bilirubin encephalopathy

Bilirubin is toxic at high levels — encephalopathy may be transient or persistent (kernicterus). Signs of bilirubin toxicity: lethargy, dehydration, pallor, irritability, hypotonia/hypertonia, seizures, fever.

Investigations

Serum bilirubin, split into conjugated (direct) and unconjugated (indirect).

Unconjugated hyperbilirubinaemia

Causes:

• Physiological jaundice — exaggerated normal response; should resolve within 2 weeks (term) or 3 weeks (preterm).
• Breast milk jaundice — common, may persist for weeks; continue breastfeeding.
• Sepsis (usually other signs present); haemolysis from blood-group incompatibility or red-cell defects (usually early onset); excessive non-haemolytic red-cell breakdown (bruising, cephalohaematoma, polycythaemia); GIT obstruction (e.g. pyloric stenosis); prematurity; hypothyroidism.

Management:

• Treat sepsis if present.
• Prolonged jaundice (>2–3 weeks) rarely needs treatment on its own.
• Discuss suspected haemolysis with haematology.
• Sunlight exposure is not recommended.
• Regular follow-up after discharge to confirm resolution and exclude signs of kernicterus; recheck bilirubin at 24–48 hrs if borderline.
• Advise parents to re-present if: stools pale/urine dark, baby unwell or feeding poorly, or jaundice persists beyond 2 weeks (term)/3 weeks (preterm).
• Phototherapy or exchange transfusion for severe jaundice.

ABO incompatibility — antibody-mediated haemolysis (mother group O, baby A or B); jaundice develops in the first 24 hours. Coombs test on the infant confirms it. Needs immediate phototherapy and ongoing developmental assessment + audiometry.

Breast milk jaundice — once other causes of prolonged unconjugated jaundice are excluded and the baby is well and breastfeeding well, this is the likely cause (~2–4% of breastfed infants). Begins later in the first week, peaks at 2–3 weeks. Diagnosis can be confirmed by briefly suspending breastfeeds and watching bilirubin fall (rarely necessary in practice).

Conjugated hyperbilirubinaemia

Defined as >15% of total bilirubin, or >15 μmol/L — indicates a possible serious cause and warrants discussion with paediatric gastroenterology.

Causes: choledochal cyst; neonatal hepatitis (infective, alpha-1 antitrypsin deficiency, idiopathic); metabolic (fructose intolerance, galactosaemia); complications of TPN; biliary atresia.

Biliary atresia

Congenital scarring of the biliary tree obstructing bile flow.

• Surgical repair (Kasai procedure) — the small bowel is attached directly to the liver — should be done before 45–60 days of life; early intervention improves outcomes.
• Outcomes: ~25% achieve good bile flow post-procedure, ~50% some flow, ~25% none. Those with no/poor flow may need liver transplantation.
• Other complications: cholangitis, failure to thrive, cirrhosis, ascites, varices.